1. Field of the Invention
The present invention relates to a wireless communication terminal and a control method therefor, and more particularly to a wireless communication terminal which switches over the choice of wireless communication system according to the state of radio wave reception, and a control method for the terminal.
2. Description of the Related Art
A dual mode wireless communication terminal is used in an environment in which a plurality of communication systems are coexistent, and switches over the choice of wireless communication system according to the state of radio wave that is received. A conventional dual mode wireless communication terminal periodically detects the reception field level of another communication system, and determines whether or not to switch over from one communication system to another on the basis of the detected level.
However, it is difficult by this method to quickly switch over from the communication system currently in use to another communication system because the level is detected at rather long intervals. On the other hand, if the intervals are shortened, the battery consumption will increase. According to the conventional method, it may sometimes be impossible to continue to use the currently chosen communication system until the next level detection. Moreover, even if the other communication system has priority, no preferential switch-over is possible.